C. Filsfils Segment Routing Use Cases Cisco Systems, Inc. · PDF fileCoS-based Traffic Engineering 4.1.2 ... – Data and UK: push the node segment to UK ... 2G from A to Z please

1 IETF-88 Vancouver, November 2013

Segment Routing Use Cases

•  Generic SR Use Cases –  draft-filsfils-rtgwg-segment-routing-use-cases-02.txt

•  SR/LDP Interoperability –  draft-filsfils-spring-segment-routing-ldp-interop-00.txt

•  OAM –  draft-geib-spring-oam-usecase-00.txt

•  To be published: –  FRR: draft-francois-segment-routing-resiliency-use-cases –  Service Chaining

–  SR for IPv6

•  Many authors of different drafts –  and even more contributors…

C. Filsfils S. Previdi

Cisco Systems, Inc.

P.Francois IMDEA Networks

B. Decraene S. Litkowski

Orange

M. Horneffer R. Geib

Deutsche Telekom

I. Milojevic Telekom Srbija

R. Shakir

British Telecom

S. Ytti TDC Oy

W. Henderickx Alcatel-Lucent

J. Tantsura

S.Kini Ericsson

E. Crabbe

Google, Inc.


Segment Routing Use Cases

Use Cases Section

IGP-based MPLS Tunneling 2

Fast Reroute 3

Disjointness in dual-plane networks 4.1.1

CoS-based Traffic Engineering 4.1.2

Egress Peering Traffic Engineering 4.1.3

Deterministic non-ECMP Path 4.1.4

Load-balancing among non-parallel links 4.1.5

Traffic engineering with Admission Control Capacity Planning SDN /SR use-case

4.2 4.2.1 4.2.2


Simple and Efficient Transport of MPLS services

•  Efficient packet networks leverage ecmp-aware shortest-path –  node segment

•  Simplification –  no complex LDP/ISIS synchronization to troubleshoot –  one less protocol to operate

•  IPv6 over MPLS can be deployed directly with SR –  no need for LDPv6

A B

M N

PE2 PE1

All VPN services ride on the node segment to PE2


CoS-based TE

•  Japan to UK –  data: via US, cheap capacity

–  voip: via Asia, low latency

•  CoS-based TE with SR –  IGP metric set such as >  Japan to Asia: via Asia

>  Japan to UK: via US

>  Asia to UK: via Europe

–  Anycast segment “Asia” advertised by Asia core routers

•  Tokyo CoS-based policy –  Data and UK: push the node segment to UK

–  VoIP and UK: push the anycast node to Asia, push UK

Node segment to UK

Node segment to Asia


•  A sends traffic with [65] Classic ecmp “a la IP”

•  A sends traffic with [111, 65] Packet gets attracted in blue plane and then uses classic ecmp “a la IP”

SR avoids state in the core

SR avoids enumerating RSVP-TE tunnels for each

ECMP paths


Engineer traffic towards egress peers

A

B C

D

E

Z

AS1

AS2

AS3

AS4

•  Ingress border routers control how their traffic is balanced between peers

–  Overriding BGP decision at egress border


Local Service Segment

•  72, 78, 65: global segments representing the shortest-path respectively to C, O and Z

•  9001: local segment to C representing a local service S1

•  9002: local segment to O representing a local service S2

•  Ingress node A enforces a source route of forwarding and service instructions on flow F by appending the SR list {72, 9001, 78, 9002, 65} on its packets

•  9001 and 9002 represent local services

A B C

M N O

Z

D

P

65 78

72

65

9001

Service S1

Service S2

9002


Application controls – network delivers

•  The network is simple, highly programmable and responsive to rapid changes

–  perfect support for centralized optimization efficiency, if required

2G from A to Z please

Link CD is full, I cannot use the shortest-path 65 straight to Z

65 FULL

65


Application controls – network delivers

•  The network is simple, highly programmable and responsive to rapid changes

Path ABCOPZ is ok. I account the BW. Then I steer the traffic on this path

FULL 66

65 68

Tunnel AZ onto {66, 68, 65}


OAM

B C

N O

A

9101 9105

9107

9104

9101

9105

9107

9108

9104

9105

Nanog57, Feb 2013

9108 9105 9108

9102

9108

9102

C. Filsfils Segment Routing Use Cases Cisco Systems, Inc. · PDF fileCoS-based Traffic Engineering 4.1.2 ... – Data and UK: push the node segment to UK ... 2G from A to Z please

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